Process of producing minium.



.tria-Hungary,

UNITED STATES PATENT OFFICE.

JLROSLAYMUHLIBAUEB, OF PRAGUE, AIlS'IRIA-HUNGARY.

success of. rnonocmo MINIUM.

1,059,195, No Drawing.

produced by roasting oxid or carbonate of lead; This process is objectionable, because the oxidation is carried out very slowly, so that even t in layers of,the oXid must be roasted fro! 24 to 28 hours before a useful product is obtained. For this. reason the efforts of those skilled in the art have for a long time been directed to finding a process by which the same result is obtained within a shorter time, and it has been tried to render the reaction more speedy b means of catalytic substances. However t ere experiments have not been successful, because catalytic substances suitable for the process have not been found. Furthermoreexperi; ments have shown, that the reaction can not be made more speedy by increasing the temperature. a

I have discovered, that the time required for the reaction can considerably be shortened by' increasing the pressure of the reacting oxygen of the air. And my invention Specification of Letters fatent. Applicatiodflled November 18, 1911. Serial No. 661,127.

consists in roasting the lead compound under pressure.

In carrying out my im roved process a lead compound such as oxi of lead is heated within iron tubes at a temperature of 460 centigrade and under-pressure. F or example,-if the process is carried out at a pressure of I12 atmospheres, within one hour a product is obtained which contains 60 per cent. of Pb O While under atmospheric pressure at'least fifteen hours would be necessary to obtain the same result. It the raw material is heated in 'the presence of pure oxygen and at a pressure of 12 atmospheres, only a few minutes are required to Patented Apr. 15,1913.

obtain a product of the same percentage of 1. The herein described process of producing minium, which consists in heating oxid of lead containing materials in the presence of an oxidizing medium under pressure.

2. The herein. described process of pro: ducing minium, which consists in heating oxid of lead containing materials in the presence of a mixture containing oxygen under pressure.

3. The herein described process of producing minium,. which consists in heating oxid of lead containing materials in the presence of oxygen under pressure.

JAROSLAV MUHLBAUER. Witnesses FERDINAND SoHULz, JosEF URBAN. 

